The invention relates to a seal. In particular, the invention relates to a seal for sealing off two bearing faces lying opposite one another.
Sealing off bearing faces which lie opposite one another is necessary, for example, where slide valves are concerned. The planar surfaces of a valve body and of a sealing disk are mounted there parallel to one another with a clearance. An orifice in the valve body enables a fluid medium, for example a cooling liquid, to flow to the valve disk. The valve disk is arranged displaceably with respect to the valve body, for example linearly or rotatably, and has an orifice which is more or less in alignment with the orifice in the valve body, depending on the position of the valve disk. The orifices may, for example, have a round or elliptic cross section. Accordingly, a flow of a fluid medium through the valve disk is dependent upon its displacement position with respect to the valve body.
In order to prevent medium from flowing through the gap between the valve disk and the valve body, it is necessary to provide a seal in this region. Such a seal usually lies in the gap and is fastened non-displaceably on one side either to the valve disk or to the valve body.
The seal is arranged in such a way that it bears under a certain pressure against the two surfaces lying opposite one another and thereby ensures leaktightness with respect to the fluid. In some applications, a clearance between the two surfaces may be variable during operation, and under some circumstances the clearance is subject to a certain variance even at the time of installation. Leaktightness of the two surfaces may be dependent upon a clearance of the bearing faces, and the result of this may be that no leaking occurs in the region of the seal in specific operating situations, for example in the case of a fluid contaminated with pollutants or in the case of different thermally induced expansions of parts of the slide valve.